JP2012030536A - Casting mold and gas-insulated switchgear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the quality of a cast-molded article using a thermosetting material and to improve the productivity of the cast-molded article.SOLUTION: A casting mold 25 has a mold body 26 having a material inlet 32 for injecting a thermosetting casting material while pressurizing it in the bottom and a plurality of cavity parts 31 formed respectively with their positions in the height direction (Z1 direction) in the mold body 26 aligned. Since each cavity part 31 is arranged with the mutual position in the height direction aligned, the casting material injected from the material inlet 32 is elevated in the mold body 26 while resisting its own weight and packed approximately simultaneously into respective cavity parts 31 to start thermosetting.

Description

  The present invention relates to a casting mold used for casting using a thermosetting material, and a gas-insulated switchgear provided with a casting manufactured using the mold.

  Epoxy resin castings have excellent electrical insulation and mechanical properties as solid insulators, and are therefore used as structural insulators installed in high-voltage substations such as gas-insulated switchgear. ing. In recent years, cast products made of epoxy resin have been required to be applied to higher-voltage power facilities and the like while ensuring long-term reliability as a solid insulator.

  As a method for producing an epoxy resin cast product, a pressure gelation method or the like is used. In the pressure gelation method, resin injection is started in a state where the inside of the mold is heated above the thermosetting temperature of the resin injected into the mold until filling of the resin into the mold cavity is completed. This is a production method in which the resin corresponding to the volume shrinkage at the time of resin curing is continuously supplied under pressure. Such a pressure gelation method can perform primary curing of a cast product in a short time, and thus enables mass production of a cast product with high quality and high reliability (see, for example, Patent Document 1).

  Today, with the expansion of overseas markets, there is a tendency for a large amount of demand to be generated for epoxy resin products in a short delivery time, and further improvement is required for the pressure gelation method described above. In other words, the pressure gelation method has the advantage of being able to manufacture a single cast product in a short time, but due to manufacturing constraints such as continuously replenishing a thermosetting casting material whose temperature is difficult to control. In general, it is common to cast a single cast for a single mold.

  On the other hand, in a general casting method in which the pressure gelation method is not applied, it is possible to take a plurality of cast products with one mold, but depending on the size of the cast product, for example, 10 In some cases, a lot of time is required, and as a result, the casting time per cast product cannot be shortened, which is not suitable for mass production.

  Specifically, in the gas insulated switchgear described above having a rated voltage exceeding, for example, 145 kV, a large number of epoxy resin solid insulators are used. However, it is assumed that insulating parts are supplied to such a device. In this case, it can be said that the known casting method to which the former pressure gelation method is applied as well as the latter general casting method has a problem in terms of production capacity.

JP 2005-53165 A

  The present invention has been made in order to solve the above-mentioned problems, and a casting mold capable of enhancing productivity while stabilizing the quality of a cast product using a thermosetting material, and An object of the present invention is to provide a gas-insulated switchgear having a cast product manufactured by using this casting mold.

  In order to achieve the above object, a casting mold according to one aspect of the present invention includes a mold main body provided with a material inlet at the bottom for injecting a thermosetting casting material while applying pressure, A plurality of cavities that are respectively formed at the same height in the mold body and filled with the casting material injected from the material injection port at the bottom of the mold body, respectively. It is characterized by comprising.

  According to the present invention, a casting mold capable of improving productivity while stabilizing the quality of a cast product using a thermosetting material, and the casting mold manufactured using the casting mold. It is possible to provide a gas insulated switchgear having a cast product.

The figure which shows the structure of the gas insulated switchgear which concerns on the 1st Embodiment of this invention. Sectional drawing which shows the structure of the connection bus line with which the gas insulated switchgear of FIG. 1 is provided. Sectional drawing which shows the structure of the post-shaped insulation spacer provided in the connection bus-line of FIG. Sectional drawing which looked at the casting mold of this embodiment used for manufacture of the insulating spacer of FIG. 3 from the direction along the parting surface. Sectional drawing which looked at the metal mold | die for casting of FIG. 4 from the direction facing a parting surface. Sectional drawing which shows the state by which injection | pouring of the casting material was started to the material injection port of the casting mold of FIG. FIG. 6B is a cross-sectional view showing a state in which the casting material is injected into the primary runner of the casting mold of FIG. 6A. FIG. 6B is a cross-sectional view showing a state in which the casting material is injected into the secondary runner of the casting mold of FIG. 6B. FIG. 6C is a cross-sectional view showing a state in which a casting material is filled in each cavity of the casting mold of FIG. 6C. Sectional drawing which shows the structure of the metal mold | die for casting which concerns on the 2nd Embodiment of this invention. Sectional drawing which shows the structure of the metal mold | die for casting which concerns on the 3rd Embodiment of this invention. Sectional drawing which shows the state by which the stop valve is open | released in the air discharge mechanism with which the casting mold of FIG. 8 is equipped. Sectional drawing which shows the obstruction | occlusion state of the stop valve in the air discharge mechanism of FIG. 9A. Sectional drawing which shows the structure of the casting mold which put the structure of 2nd Embodiment in the casting mold of FIG. Sectional drawing which shows the structure of the metal mold | die for casting which concerns on the 4th Embodiment of this invention. The disassembled perspective view which shows the structure of the nesting with which the casting mold of FIG. 11 was equipped. Sectional drawing which shows the structure of the casting mold which put the structure of 3rd Embodiment in the casting mold of FIG.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
[First Embodiment]
As shown in FIG. 1, a gas insulated switchgear (GIS: Gas Insulated Switchgear) 1 according to this embodiment includes main busbars 12 and 14 and a bushing 21 and is filled with sulfur hexafluoride (SF6) gas. The open / close facility accommodates the disconnectors 15 and 16, the circuit breaker 17, the current transformer 18, the connection bus 19, and the like in the grounded container. For example, when breaking the current, the breaker 17 described above extinguishes the discharge by blowing the sulfur hexafluoride gas having high insulation between the arc-discharged electrodes of the switch.

  As shown in FIG. 2, the connection bus 19 is configured in such a manner that a high-voltage conductor 22 for energizing current is housed inside a connection container 20 having a ground potential. The high voltage conductor 22 is supported in the connection container 20 via the cone-shaped (conical) insulating spacers 23 and 24 and the post-shaped insulating spacer 3. The cone-shaped insulating spacers 23 and 24 support the high voltage conductor 22 while isolating the sulfur hexafluoride gas inside the connection container 20.

  Here, the structure of the post-shaped insulating spacer 3 will be described. As shown in FIGS. 2 and 3, the post-shaped insulating spacer 3 is formed by integrally molding a spacer main body 5 made of epoxy resin and a set of embedded fittings 7 and 8 which are metallic embedded members. It consists of cast products. The spacer main body 5 having electrical insulation is formed in a barrel shape in which a central portion of a cylinder is expanded.

  As shown in FIGS. 2 and 3, a set of embedded metal fixtures 7 and 8 is provided at each end of the spacer body 5. As shown in FIG. 2, one embedded metal 7 is mechanically connected to the high voltage conductor 22, and the other embedded metal 8 is mechanically connected to the inner portion of the connection container 20. Thus, the insulating spacer 3 supports the high voltage conductor 22 on the inner wall surface of the connection container 20 from the bottom side in a posture in which the axial direction of the insulating spacer 3 is raised.

  An epoxy resin, which is a thermosetting casting material, is applied to the material of the spacer body 5. More specifically, as this epoxy resin, an acid anhydride curing agent and alumina as an inorganic filler blended in a liquid bisphenol A epoxy resin are used.

  In addition, on the bulging peripheral surface of the spacer body 5, there are formed concavo-convex portions constituting a plurality of steps in a stepped manner from the central portion toward each end in the axial direction of the insulating spacer 3. Yes. The uneven portion is formed to roughen the surface of the spacer main body 5 on the order of several microns, for example. Thereby, this uneven | corrugated | grooved part functions so that the movement of an electron may be inhibited, and charging of spacer main-body part 5 itself is suppressed.

  Next, the structure of the casting mold 25 for manufacturing (casting) the post-shaped insulating spacer 3 will be described. As shown in FIGS. 4 and 5, the casting mold 25 includes a mold body 26 having a fixed mold part 30 and a movable mold part 29 movable in the direction of the arrow X1-X2, and a movable mold part 26. Mold fixing plates 37 and 38 to which the side mold part 29 and the fixed mold part 30 are fixed, respectively, and a nesting 27 mounted inside each of the movable mold part 29 and the fixed mold part 30; 28.

  Here, the casting mold 25 of the present embodiment is of a specification that takes a plurality of insulating spacers 3 as cast products (six in this embodiment) while applying a so-called pressure gelation method. It is a mold. That is, a material injection port 32, a plurality of cavities (mold cavities) 31, a mold body 26 composed of the movable mold part 29 and the fixed mold part 30 of the casting mold 25, A runner 40, a material reservoir 46, and the like are formed.

  The material injection port 32 is provided at the bottom of the mold body 26, and a sprue (pouring gate) for injecting a thermosetting casting material into the mold body 26 while applying pressure from the outside of the mold body 26. It is. Each cavity part 31 is comprised by the recessed part (dent part) each corresponding to the shape of a product. The runner portion 40 constitutes a casting material transfer path that leads from the material injection port 32 to the individual cavity portions 31.

  The material reservoir 46 is formed on the upper side of each cavity part 31 and accommodates the casting material extruded from the cavity part 31 side when the casting material is filled in each cavity part 31. Further, the material reservoir 46 accommodates air remaining in the cavity portion 31 that is pushed out from the cavity portion 31 together with the casting material (air causing void generation). In the mold body 26, a relay path 45 that connects the material reservoir 46 and each cavity 31 is provided.

In addition, each cavity part 31 carries out the thermosetting of the casting material with which each inside was filled, for example, the spacer main-body part 5 of the size which exceeds 7000 cc (cm < ³ >) and exceeds the maximum thickness exceeds 170 mm. The shape can be obtained as a cast product.

  As shown in FIGS. 4 and 5, for example, a hydraulic cylinder 39 is connected to a mold fixing plate 37 that fixes the movable mold part 29. The cylinder 39 opens and closes the casting mold 25 by moving the movable mold part 29 forward and backward with the mold fixing plate 37 with respect to the fixed mold part 30. Further, the casting material transferred via the material transfer pipe 34 is provided at the bottom of the mold body 26 in the casting mold 25, and the material injection port 32 is provided in the cavity portion 31 of the mold body 26. A material injection nozzle 33 for injecting (filling) is disposed.

  On the base end side of the material transfer pipe 34, a liquid injection resin, which is a thermosetting casting material, is injected into the cavity 31 of the mold body 26 with a material injection nozzle 33 and a material injection port 32. A cylinder mechanism or the like having a piston for replenishing pressure is connected through the cylinder.

  Further, the casting mold 25 of the present embodiment is provided with a heating mechanism 36 including a temperature sensor disposed in the vicinity of the cavity portion 31 and a plurality of rod-shaped heaters 35 that can be controlled in temperature. Yes. The heater 35 described above is built in a mold body 26 configured by a movable mold part 29 and a fixed mold part 30 in a grid pattern. The heating mechanism 36 heats (heats control) the mold body 26 so that the heating temperature increases from the bottom to the top of the mold body 26.

  Specifically, when the insulating spacer 3 is cast, the heating mechanism 36 is disposed in the vicinity of the material injection port 32 below the respective cavity portions 31 in the mold body 26 shown in FIGS. The upper part including the formation part of each cavity part 31 in the mold body 26 shown in FIGS. 4 and 5 is heated to about 130 ° C. to 140 ° C., for example.

  In other words, when the insulating spacer 3 is cast, the heating mechanism 36 is used to prevent the casting material near the material inlet 32 from being first thermally cured during the casting transition period. The mold main body is provided with a temperature gradient so that the temperature near the material injection port 32 is, for example, about 10 ° C. to 20 ° C. lower than, for example, the upper portion including the formation portion of the cavity portion 31 in 26. The inside 26 is temperature controlled.

  Furthermore, the characteristic structure which the casting mold 25 of this embodiment has will be described. As shown in FIG. 5, the runner portion 40 includes a primary runner 41 that bifurcates from the upper end portion of the material injection port 32 and extends in the horizontal direction (arrow Y1-Y2 direction), and a cavity portion from the middle of the primary runner 41. And a secondary runner 42 extending in the direction of rising toward 31 (in the direction of arrow Z1). Each end (upper end) portion of each secondary runner 42 is configured as a gate 43 and opens in each cavity portion 31.

  Here, as shown in FIG. 5, the individual cavity portions 31 are formed so as to be aligned with each other in the height direction (arrow Z <b> 1 direction) in the mold body 26. That is, the cavities 31 are arranged in a state of being regularly arranged in the mold body 26 along the horizontal direction (arrow Y1-Y2 direction). Therefore, the casting material supplied to the primary runner 41 through the material injection port 32 is filled in the entire primary runner 41 and then rises in the secondary runner 42 in the direction of the arrow Z1 while resisting its own weight. The individual cavities 31 are filled almost simultaneously. As a result, it is possible to suppress variations in the heating time for the casting material in the individual cavities 31, so that the electrical insulation properties and mechanical properties of each of the thermosetting casting products (insulating spacers 3) can be reduced. Various characteristics including the characteristics can be made uniform.

  The runner portion 40 and each cavity portion 31 are configured so as to have a substantially symmetrical layout (on the right side and the left side in FIG. 5) with the position of the material injection port 32 in the mold body 26 as a reference. Yes. Thereby, on the right side and the left side of the material injection port 32, the transfer time of the casting material transferred to the primary runner 41 and the secondary runner 42 of the runner 40 (or the heating time after filling the cavity 31) ) In the same manner, and various types of (three) cast products cast on the right side in FIG. 5 and (three) cast products cast on the left side in FIG. Variations in characteristics can be suppressed.

  In addition, as shown in FIG. 5, each cavity part 31 is comprised so that a cast may be cast in the state which each inclined. This structure is a configuration for preventing the flow of the casting material from being hindered by physical interference between the embedded metal fittings 7 and 8 mounted in the cavity portion 31. As a result, when the casting material is filled into the cavity portion 31, the air remaining in the cavity portion 31 together with the excess casting material is easily pushed out, and generation of voids can be suppressed.

  Next, a manufacturing method of the insulating spacer 3 using the casting mold having such a structure will be described based on FIGS. 6A to 6D in addition to FIGS. 3 to 5 described above. As illustrated in FIG. 5 and the like, first, the embedded metal objects 7 and 8 are attached to the inserts 27 and 28 with an O-ring interposed therebetween. Next, the inserts 27 and 28 to which the embedded metal fixtures 7 and 8 are attached are connected to the mold parts on the predetermined side of the mold body 26, that is, the movable mold part 29 and the fixed mold part 30. Set (install) one of them.

  Subsequently, as shown in FIG. 4, the casting mold 25 in which the inserts 27 and 28 are set is placed so that the parting surfaces 26a of the movable mold part 29 and the fixed mold part 30 are in contact with each other. After closing through the cylinder 39, the inside of the mold body 26 in the casting mold 25 is heated. At this time, the portion excluding the vicinity (periphery) of the material injection port 32 in the mold body 26 shown in FIG. 4 is heated to 135 ° C., and the vicinity of the material injection port 32 is heated to 125 ° C., which is 10 ° C. lower. As described above, the temperature is adjusted through the heating mechanism 36. Such temperature adjustment is performed in order to suppress thermosetting of the casting material 48 at the material inlet 32.

Next, after the inside of the mold body 26 is evacuated, for example, and the inside of the mold body 26 is adjusted to the above heating temperature, as shown in FIG. 6A at an injection speed of 50 cc (cm ³ ) / sec from the material injection nozzle 33. Then, injection of the thermosetting casting material 48 (liquid epoxy resin) into the material injection port 32 is started.

  Thereafter, as shown in FIG. 6A, the casting material 48 branches from the upper end of the material injection port 32 along the primary runner 41 extending in the horizontal direction (arrow Y1-Y2 direction). Subsequently, as shown in FIG. 6B, the casting material 48 is filled in the entire primary runner 41. Further, thereafter, as shown in FIG. 6C, the casting material 48 rises in the direction of the arrow Z1 while resisting its own weight in the secondary runner 42 extending in the vertical direction. Further, as shown in FIG. 6D, the casting material 48 is filled into the individual cavity portions 31 through the gates 43 at approximately the same time.

  At this time, by controlling a cylinder mechanism including a piston on the proximal end side of the material transfer pipe 34, the volume at the time of resin curing by a crosslinking reaction is introduced into each cavity portion 31 of the heated mold body 26. The casting material 48 is pressurized and replenished to compensate for the shrinkage. By pressurizing and replenishing the casting material 48 (replenishment while pressurizing), as shown in FIG. 6D, the outer peripheral portion of the casting material 48 in each cavity portion 31 of the mold body 26 is thermally cured. A semi-cured product is obtained. Furthermore, by continuing this pressurization of the casting material 48, the heat of reaction during the crosslinking reaction that occurs when the thermosetting of the semi-cured product obtained in the mold body 26 proceeds to the center side. Then, the semi-cured product is internally heated from the center.

  Next, after the pressurization of the casting material 48 is stopped, the semi-cured material is taken out (released) from the cavity 31 of the mold body 26, and the inserts 27 and 28 are removed from the semi-cured material. Remove. Next, the semi-cured product taken out from the mold body 26 is left, for example, for about 30 minutes, and the internal heat generation of the semi-cured product is continued to thermally cure the entire semi-cured product including the central portion. As shown in FIG. 3, a post-type insulating spacer (cast product) 3 having final physical properties as a solid insulating material such as high heat resistance is obtained.

  As described above, in the casting mold 25 of the present embodiment, as shown in FIGS. 5 and 6B to 6D, the individual cavity portions 31 are arranged in the height direction within the mold body 26. Since the respective positions in the direction of the arrow Z1 are aligned, it is possible to fill the casting material 48 into the respective cavity portions 31 almost at the same time. Therefore, according to the casting mold 25, the heating period of the casting material in each cavity portion 31 can be made substantially the same, and a plurality of cast parts (insulating spacer 3) that are thermally cured are obtained. Various characteristics including mechanical strength, heat resistance, electrical insulation and the like can be made uniform. Thereby, in addition to being able to manufacture the insulating spacer 3 with stable quality, productivity can be improved.

  Further, in the casting mold 25, as described above, the cavity portions 31 are arranged with their positions in the mold body 26 aligned in the height direction. It is possible to stabilize the characteristics of the cast product with relatively simple temperature control such as controlling the heating temperature only. Further, the post-type insulating spacer 3 that stabilizes the quality as a solid insulator is applied to the supporting portion of the high-voltage conductor 22 as shown in FIGS. The reliability of the insulation of the switchgear 1 can be improved.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. In FIG. 7, the same components as those in FIG. 5 described in the first embodiment are given the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 7, the casting mold 58 of this embodiment is a mold capable of taking eight castings, and has six castings of the first embodiment. Instead of the runner 40 provided in the casting mold 25, a runner 50 is provided. The runner portion 50 is formed so as to constitute the respective transfer paths of the casting material that lead from the material injection port 32 to the individual cavities 31 and to align the lengths of these transfer paths.

  That is, the runner unit 50 includes primary to sixth runners 51 to 56. The primary runner 51 is bifurcated from the upper end of the material injection port 32 and extends in the horizontal direction (arrow Y1-Y2 direction). The secondary runner 52 extends from each end of the primary runner 51 in the upper side direction of the casting mold 58 (in the direction of the arrow Z1). The tertiary runners 53 are bifurcated from the upper ends of the two secondary runners 52 and extend in the horizontal direction.

  Further, the fourth runner 54 extends from each end of the tertiary runner 53 toward the upper side of the casting mold 58, and the fifth runner 55 extends from each upper end of the four fourth runners 54 to the second hand. It branches and each extends horizontally. The sixth runner 56 has the same structure as the secondary runner 42 of the first embodiment.

  More specifically, the runner portion 50 and each cavity portion 31 are configured so as to have a substantially symmetrical layout (on the right side and the left side in FIG. 7) with the position of the material injection port 32 in the mold body 26 as a reference. Has been. As described above, the runner portion 50 that branches in stages, such as two, four, and eight, is such that each transfer path of the casting material leading from the material injection port 32 to each cavity portion 31 has a mutual path length. It is formed to be equal.

  Therefore, in the casting mold 58 of the present embodiment, in addition to being able to equalize the heating period of the casting material in each cavity portion 31 as in the first embodiment, It becomes possible to equalize the transfer time (heating time) of the casting material until it reaches each of the cavities 31. Thereby, according to the casting mold 58, it is possible to suppress variations in various characteristics of each of the thermosetting cast products.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIGS. 8 to 10, the same reference numerals are given to the same components as those in FIGS. 5 and 7 described in the first and second embodiments, and the description thereof is omitted.

  As shown in FIGS. 8, 9A, and 9B, the casting mold 60 of this embodiment further includes an air discharge mechanism 61 in addition to the configuration of the casting mold 25 according to the first embodiment. ing. The air discharge mechanism 61 includes a plurality of air discharge holes 62 communicating from the individual cavity portions 31 to the outside of the mold body 26, and a plurality of air discharge holes 62 as the casting material is filled into the respective cavity portions 31. And a plurality of stop valves 63 as valve members that respectively close the valve.

  Specifically, as shown in FIGS. 8, 9A and 9B, the air discharge holes 62 are configured as stepped holes that open from the individual material reservoirs 46 to the outside of the mold body 26, and are inclined surfaces. 64 is provided in the central portion. As shown in FIGS. 9A and 9B, the air discharge hole 62 is configured with a large-diameter hole portion 65 on the material reservoir 46 side (bottom side), and a small-diameter hole portion on the upper side that opens to the outside of the mold body 26. 66. On the other hand, the stop valve 63 includes a shaft portion 67 extending in the vertical direction (arrow Z1-Z2 direction) and a conical portion 68 provided at the lower end of the shaft portion 67.

  As shown in FIGS. 9A and 9B, the shaft portion 67 of the stop valve 63 is formed with a diameter smaller than that of the small-diameter hole portion 66 of the air discharge hole 62, and is inserted into the small-diameter hole portion 66. Yes. That is, a predetermined gap (clearance) is formed between the narrow hole portion 66 and the shaft portion 67. On the other hand, the conical portion 68 of the stop valve 63 is disposed in the large-diameter hole portion 65 of the air discharge hole 62.

  As shown in FIG. 9B, the air discharge mechanism 61 having such a structure has a mold body 26 in a closed state where the conical portion 68 of the stop valve 63 contacts the inclined surface 64 of the air discharge hole 62. The material reservoir 46 and the cavity 31 side are closed with respect to the outside. On the other hand, as shown in FIG. 9A, when the stop valve 63 is in an open state in which the conical portion 68 of the stop valve 63 is separated from the inclined surface 64 of the air discharge hole 62, the material reservoir 46 is located outside the mold body 26. And the cavity part 31 side will be in the open state.

  That is, until the state immediately before the casting material 48 is filled in the cavity 31 and the material reservoir 46, as shown in FIG. 9A, the stop valve 63 is pushed down by its own weight in the direction of the arrow Z2, and the stop valve 63 is It becomes an open state. As a result, the air remaining in the cavity 31 and the material reservoir 46 can be easily released to the outside of the mold body 26 through the air discharge hole 62.

  On the other hand, in the state where the casting material 48 is filled into the cavity 31 and the material reservoir 46, as shown in FIG. 9B, the stop valve 63 is moved in the direction of the arrow Z1 by the applied pressure when filling the casting material 48. The stop valve 63 is closed. In this case, since the air discharge hole 62 is closed, the casting material 48 is prevented from leaking. Further, as shown in FIG. 10, a casting mold 69 in which such an air discharge mechanism 61 is added to the casting mold 58 of the above-described second embodiment can also be configured. It is.

  Therefore, in the casting molds 60 and 69 of the present embodiment, the air in the cavity portion 31 can be effectively removed while suppressing the filling leakage of the casting material 48. Thereby, in addition to suppressing the generation of voids that cause a decrease in the electrical insulation performance of the insulating spacer 3 (casting product), the filling property of the casting material 48 into the cavity portion 31 is enhanced. Stable castings can be obtained.

[Fourth Embodiment]
Next, the 4th Embodiment of this invention is described based on FIGS. 11 to 13, the same reference numerals are given to the same components as those in FIGS. 5 and 8 described in the first and third embodiments, and the description thereof is omitted.

  The casting mold 70 according to this embodiment is replaced with the post-shaped insulating spacer 3 integrally cast together with the embedded molds 7 and 8 by the casting mold 25 according to the first embodiment, as shown in FIGS. As shown in FIG. 12, it is a mold capable of casting a pole-shaped insulating spacer 73 which is entirely composed of only a casting material without an embedded metal. The insulating spacer 73 has a cut-off shaft shape, and has a spacer main body 72, a diameter smaller than that of the spacer main body 72, and a narrow diameter portion 74 formed at both ends of the spacer main body 72. Is provided. This pole-shaped insulating spacer 73 is also disposed as a solid insulator inside the gas-insulated switchgear 1 shown in FIG.

  Specifically, the casting mold 70 of this embodiment is a mold body 75 in place of the mold body 26 and the inserts 27 and 28 included in the casting mold 25 described in the first embodiment. And four nestings 77 and a nesting fixing mechanism 80. The mold body 75 has a fixed mold part 75b and a movable mold part 75a that can move in the directions of arrows X1-X2. In addition, a plurality of cavity portions 71 are formed in the mold body 75 so as to align the positions in the height direction within the mold body 75.

  Each insert 77 holds a plurality of insulating spacers 73 (cast products) cast in each cavity portion 71 integrally and detachably. That is, each nesting 77 includes a movable nesting portion 78 that is detachably attached to the movable mold portion 75a, a fixed nesting portion 79 that is inserted in a state where there is a gap in the fixed mold portion 75b, So-called two-piece structure.

  The movable-side nesting part 78 and the fixed-side nesting part 79 are provided with a plurality of recesses 78a and 79a recessed in a semi-cylindrical shape, respectively. The individual small diameter portions 74 at both ends are held by these concave portions 78a and 79a so as to be sandwiched. That is, the fixed side nesting part 79 and the movable side nesting part 78 are integrally fastened by tightening the screw 79b inserted into the fixed side nesting part 79 into the screw hole 78b provided in the movable side nesting part 78. A nest 77 is formed.

  The casting mold 70 is provided with a nesting fixing mechanism 80 that detachably fixes the nesting 77 to either one of the fixed-side mold part 75b and the movable-side mold part 75a. In the present embodiment, a structure in which the insert 77 is detachably fixed to the movable mold part 75a is illustrated.

  That is, the movable side insert part 78 is provided with a plurality of press-fit pins 78c so as to protrude, and these press-fit pins 78c are O to the pin press-fit holes 75c previously drilled in the movable side mold part 75a. It is press-fitted (fixed detachably) through a ring or the like. On the other hand, a concave portion having a size slightly larger than the outer shape of the fixed nesting portion 79 is formed in the fixed mold portion 75b, and the fixed nesting portion 79 is inserted into the concave portion in a non-press-fit state. .

  Therefore, in the casting mold 70 of this embodiment, before the casting of the insulating spacer 73 is started, the nesting 77 in which the fixed side nesting portion 79 and the movable side nesting portion 78 are integrally fastened is used as the movable side die. The mold body 75a is set (removably fixed), and the mold body 75 is closed. After casting the insulating spacer 73, the movable side nest part 78 is retracted in the direction of the arrow X2, and the mold body 75 is opened. At this time, since the narrow diameter portion 74 of the insulating spacer 73 is held between the concave portions 78a and 79a, and the movable side nested portion 78 of the insert 77 is fixed to the movable mold portion 75a, all In the cast product (insulating spacer 73), the mold body 75 is opened while being fixed to the movable mold part 75a.

  Thereafter, the fixed-side nesting portion 79 and the movable-side nesting portion 78 in the nesting 77 removed from the movable-side mold portion 75a are separated into two by removing the screw 79b, so that a plurality of insulations as cast products are obtained. Each of the spacers 73 can be removed from the mold body 75 and the insert 77.

  Thus, in the casting mold 70 of the present embodiment, when the mold body 75 is opened after casting, either one of the fixed mold part 75b and the movable mold part 75a ( In this embodiment, the insulating spacer 73 that is a cast product can be fixed to the movable mold part 75 a side), and the individual insulating spacers 73 that are cast are inserted through the insert 77 having a two-piece structure. Can be removed efficiently. That is, according to the casting mold 70, it is possible to easily release the insulating spacer 73 that is entirely composed of only the casting material without any embedded metal, for example, without being damaged. As shown in FIG. 13, it is possible to configure a casting mold 81 in which the air discharge mechanism 61 of the third embodiment is added to the casting mold 70 of the present embodiment.

  Although the present invention has been specifically described above with reference to the embodiment, the present invention is not limited to this embodiment, and various modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment, the epoxy resin is exemplified as the thermosetting casting material. However, instead of this, for example, a silicone resin blended with a predetermined curing agent and a filler may be applied. .

  DESCRIPTION OF SYMBOLS 1 ... Gas insulation switchgear, 3, 73 ... Insulation spacer (casting product), 25, 58, 60, 69, 70, 81 ... Mold for casting, 26, 75 ... Mold main body, 27, 28, 77 ... Nest, 29, 75a ... Movable mold part, 30, 75b ... Fixed mold part, 35 ... Heater, 36 ... Heating mechanism, 31, 71 ... Cavity part, 32 ... Material injection port, 40, 50 ... Runner portion, 46 ... resin reservoir, 48 ... casting material, 61 ... air discharge mechanism, 62 ... air discharge hole, 63 ... stop valve (valve member), 80 ... nesting fixing mechanism.

Claims (6)

A mold body provided with a material inlet at the bottom for injecting a thermosetting casting material while applying pressure;
A plurality of cavities each formed by aligning the positions in the height direction in the mold body and filled with the casting material injected from the material injection port at the bottom of the mold body; and
A casting mold characterized by comprising: A heating mechanism that heats the mold body so that the heating temperature increases from the bottom to the top of the mold body;
The casting mold according to claim 1, further comprising: A runner portion formed so as to constitute each transfer path of the casting material that leads from the material injection port to each of the cavity portions and to align the lengths of these transfer paths, respectively.
The casting mold according to claim 1, further comprising: A plurality of air discharge holes respectively communicating from the individual cavity portions to the outside of the mold body, and a plurality of valve members respectively closing the plurality of air discharge holes as the casting material is filled into the cavity portions. An air discharge mechanism,
The casting mold according to any one of claims 1 to 3, further comprising: The mold body has a fixed mold part and a movable mold part movable,
A nest that holds a plurality of cast products cast in each of the individual cavity portions integrally and detachably,
A nesting fixing mechanism for detachably fixing the nesting to either one of the fixed mold part and the movable mold part;
The casting mold according to any one of claims 1 to 4, further comprising:   A gas-insulated switchgear comprising a cast product manufactured using the mold according to any one of claims 1 to 5.

Images